Exam 3- The Hepatobiliary System, Gall Bladder and Pancreas

Question 1

What’s the point of tight junctions between hepatocytes?

Answer 1

to separate the biliary secretion from the blood supply

Question 2

T/F: the arrangment of hepatocytes maximizes their area of contact with blood.

Answer 2

True!

Question 3

Branching of the hepatic portal vein and hepatic artery leads to ________, the functional units within the liver.

Answer 3

the liver lobules

Question 4

What are three liver lobules?

Answer 4

classical lobule, portal lobule, and acinar lobule

Question 5

The classic lobule is ______ in shape and has plates of _______ arranged radially around a _______.

Answer 5

hexagonal; hepatocytes; central vein

Question 6

What are at each vertices of the hegaonal classical tubule? (3)

Answer 6

• interlobular vessels (hepatic protal vein + hepatic artery)
• bile duct
• Space of Mall (lymphatic Space)

Question 7

What makes up the portal triad? (two)

Answer 7

-interlobular vessels + bile duct

Question 8

What distributes blood into the sinusoids between the plates of haptocytes?

Answer 8

Distributing or perilobular branches (branches from the interlobular vessels)

Question 9

Describe the thickness of the hepatic plate

Answer 9

it is one hepatocyte cell thick so that two side of hepatocytes are exposed to plasma

Question 10

A network of tiny bile canaliculi run within the plates of hepatocytes, sealed from exposure to the blood by _______ between hepatocytes.

Answer 10

zonulae occludens

Question 11

What is the “bile secretory” functional unit of the liver lobule?

Answer 11

The portal lobule

Question 12

Describe the portal lobule….

Answer 12

a zone of tissue around a bile duct into which a group of bile canaliculi feed- “bile Secretory” function unit

Question 13

What functional unit of the liver lobule is involved with blood delivery?

Answer 13

The Acinar Lobule

Question 14

The axis of the acinar lobule:
_____: lies between two portal triads
_____: lies between two central veins

Answer 14

“short axis”; “long axis”

Question 15

The distributing branches of the interlobular vessels run along the “edges” of a ________, but run along the ______ of the acinar lobule.

Answer 15

classical lobule; “short axis”

Question 16

Where does glycogen tend to accumulate more efficiently in hepatocytes?

Answer 16

the central zone of the acinar lobule

Question 17

Exposure to toxins leads to degeneration nearest the _______, but lack of oxygenation or nutrients affects hepatocytes neaures the _____.

Answer 17

distributing vessels; central veins

Question 18

What are three liver lobules?

Answer 18

classical lobule, portal lobule, and acinar lobule

Question 19

What are the functions of hepatocytes? (4)

Answer 19

• take up glucose/ converts into glycogen
• produce major blood proteins
• detoxifies by conjugating w/ glucuronic acid
• takes up bilibrubin from the spleen

Question 20

What are the major blood proteins produced by hepatocytes?

Answer 20

albumin, glycoproteins (fibrinogen/ prothrombin) and lipoproteins

Question 21

How does hepatocytes detoxify lipid-soluble toxins?

Answer 21

conjugates them with glucuronic acid

Question 22

Excess cholesterol is eliminated in ____.

Answer 22

bile

Question 23

What are 3 characteristics of the hepatocyte plasma membrane?

Answer 23

• microvilli (aids in absorptive process)
• every hepatocyte exposed to plasma components
• contains secretory organelles (rough/smooth ER, golgi, secretory vesicles, lysosomes/ peroxisomes, lipid droplets)

Question 24

What are the functions of hepatocytes? (4)

Answer 24

• take up glucose/ converts into glycogen
• produce major blood proteins
• detoxifies by conjugating w/ glucuronic acid
• takes up bilibrubin from the spleen

Question 25

Hepatocytes facing the sinusoids have what type of endothelial cells? What's the purpose of it?

Answer 25

fenestrated

Question 26

The fenestrated epithelium of hepatocytes facing the sinusoids allows/ disallows what to pass?

Answer 26

allows- plasma components/ lipoproteins | disallows- RBCs

Question 27

The space between endothelial cells and the hepatocyte is called the _________, which contains a meshwork of _______ that provides support for the sheets of hepatic cells, endothelial cells on top of them and Kupffer Cells.

Answer 27

perisinusoidal space (space of Disse); reticular fibers

Question 28

What's the point of the meshwork of reticular fibers within the perisinusoidal space (space of Disse)

Answer 28

provides support for the sheets of hepatic cells, endothelial cells on top of them and Kupffer Cells.

Question 29

What's the function of Kupffer cells? How are they distinguishable from the standard endothelial cells?

Answer 29

they play a defense role in the liver they have larger nuclei and phagocytizes particulate materials (look for in histology)

Question 30

Bile Salts are cholate derivatives that contains what? (6)

Answer 30

cholesterol, phospholipids, electrolytes, bilirubin glucuronides, proteins and dimeric IgA

Question 31

Bile canaliculi are surrounded by plasma membranes of adjacent hepatocytes with extensive microvilli in the lumen. Here, hepatocytes are connected by _________ to prevent what?

Answer 31

tight junctions; prevents leakage of bile

Question 32

Bile canaliculi lead to ______, which are surrounded by a cuboidal layer of epithelial cells and have microvillar projections into the lumen.

Answer 32

canals of Hering

Question 33

Bile salts are largely recycled. How?

Answer 33

when they pass through the intestine, they are reabsorbed by the intestinal mucosa and taken up by the liver

Question 34

What the steps of bile canaliculi leading to the common hepatic duct (6 total)

Answer 34

Bile Canaliculi > Canals of Hering > Interlobular Bile Ducts > Lobar Ducts > Common Hepatic Duct NOTE- all of the epithelial cells have numerous microvilli and are involved in electrolyte transport and absorption of H2O

Question 35

Descrribe the epithelial lining of the interlobular bile ducts as it forms into the lobar ducts.

Answer 35

it is initially cuboidal but becomes columnar as the ducts fuse

Question 36

The gall bladder is connected to the common hepatic duct via the ________; these ducts fuse to form the _______ that joins the pancreatic duct and enters the duodenum.

Answer 36

cystic duct; common bile duct

Question 37

What are two sphincters that control bile release into the duodenum?

Answer 37

The sphincter choledochus/ spincter of Boyden (before entry of the pancreatic duct) and the sphincter of Oddi (after entry of the pancreatic duct)

Question 38

What leads to bile secretion? How does it do this?

Answer 38

Cholecystokinen; it releases enteroendocrine cells to induce gall bladder contraction and spincter relaxation

Question 39

The _______ stores and concentrates bile.

Answer 39

Gall Bladder

Question 40

Describe the apical surface and basolateral surfaces of the gall bladder.

Answer 40

Apical Surface- extensively folded mucosal layer; numerous microvilli and tight junctions Basolateral Surface- folded to allow transport of solt into the BL spaces between cells; H2O will follow (via osmosis)

Question 41

What are two hormones produced by enteroendorcine cells of the small intestine that controls secretion of the exocrine pancrease?

Answer 41

secretin and cholecystokinin

Question 42

What helps neutralize stomach acid?

Answer 42

pancreatic secretion (bicarbonate-rish solution) secreted by pancreatic ducts

Question 43

What are the functional units of pancreatic exocrine cells? describe them

Answer 43

acini- polarized epithelial arranged around a central lumen that joins a duct

Question 44

________ represent the beginning of the pancreatic duct system.

Answer 44

Centroacinar cells

Question 45

T/F: hydrolytic enzymes synthesized by the pancrease are in the active form. They includ trypsin, chymotrypsin, elastase, carboxypeptidase, and triacyl-glycerol lipase.

Answer 45

False; IN-ACTIVE form

Question 46

What are 5 enzymes produced by hydrolytic enzymes of the pancrease?

Answer 46

trypsin, chymotrypsin, elastase, carboxypeptidase, and triacyl-glycerol lipase

Question 47

What's the function of bile salts?

Answer 47

emulsify fat